Introducing IEEE 802.11r

On July 15th of this year, without much fanfare, the IEEE published the final specification for IEEE 802.11r-2008, also known as Fast Basic Service Set Transition, an amendment to the 802.11 standard that supports fast handoff between access points--specifically in order to enable VoIP roaming on a Wi-Fi network with 802.1X authentication.

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The new amendment to the 802.11 standard supports VoWi-Fi handoff between access points.

On July 15th of this year, without much fanfare, the IEEE published the final specification for IEEE 802.11r-2008, also known as Fast Basic Service Set Transition, an amendment to the 802.11 standard that supports fast handoff between access pointsspecifically in order to enable VoIP roaming on a Wi-Fi network with 802.1X authentication.

Kelly Davis-Felner, senior director for the Wi-Fi Alliance, says the key strength of the new standard lies in the fact that it brings the handoff time between APs down to below the 50 millisecond mark, which, she says, is widely accepted as the point at which it would be perceptible on a voice call.

One significant benefit of the arrival of 802.11r as a standard, Davis-Felner says, will be the ability of corporate networks to use multiple vendors. Industry standards benefits everybodybig guys, small guys and end usersbut perhaps the biggest beneficiary is going to be the IT manager whos trying to a build a Wi-Fi network that people can use with their handsets, she says.

And Davis-Felner says 802.11r meshes well with the Wi-Fi Alliances planned Voice-Enterprise certification program, scheduled to begin next year as an enhancement to the Voice-Personal certification. It adds elements of rit adds the security/authentication component of it, which you dont see in a home environment, she says.

An easier sell

Stan Schatt, vice president and research director for wireless connectivity at ABI Research, says 802.11r inevitably faced fewer battles in its approval process than a more fundamentaland therefore more contentiousstandard, such as 802.11n. When youre talking about something like n, vendors are fighting to retain their time-to-market advantage, whereas r is basic middleware so youre not making any fundamental changes in your manufacturing process, he says.

Schatt says the new standard should be a boon both for smaller fixed-mobile convergence (F/MC) players and for smaller Wi-Fi equipment vendors. It means that customers will be able to mix and match a little more than they have in the past, he says. Whenever you have standards, it kind of levels the playing field, because you dont have to invest so much in programming and R&D.

Key markets for voice over Wi-Fi (VoWi-Fi), Schatt says, include hospitals, manufacturing facilitiesand educational institutions. In higher education, youve got faculty and administrators who are constantly moving around from building to building for classes, and this allows them to be in constant contact, he says.

And the next big step for the VoWi-Fi market, Schatt says, will be to provide support for 802.11n phoneswhich he doesnt expect to see for another few years. In three years, n is going to dominate the market so thoroughly that economies of scale will certainly drive the price downand the battery life technology will be much better then, too, he says.

Increasing security

Geri Mitchell-Brown, director of technical business development for Polycom and chair of the Wi-Fi Alliances VoWi-Fi marketing task group, says 802.11rs real strength lies in its support for 802.1X security. If youre going to do WPA2-Enterprise, which requires 802.1X authentication, in a client device that has a delay-sensitive application, you need some kind of fast roaming mechanismand thats what 802.11r delivers, she says.

The point, Mitchell-Brown says, is that enabling a higher level of security in devices that support real-time applications is key to making the wireless LAN equivalent to the wired LAN. If you can offer the same level of security for any application, then youre moving towards that ability to have the all-wireless office and 802.11r is a key component of that, she says.

Still, Mitchell-Brown says Polycom wont likely implement 802.11r until Voice-Enterprise is rolled out and supported by WLAN manufacturers. Our timeframes are based on support in the wireless LAN, which I expect to be driven by the Voice-Enterprise certification program in late 09 the launch of the certification program by the Wi-Fi Alliance will be the driving factor for vendors to implement it, she says.

At the same time, the Wi-Fi Alliances Davis-Felner says this is the right time for the arrival of a standard like 802.11r. Most analysts are saying that handsets are going to be about a third of the Wi-Fi market in a couple of yearsand this is a major enabler of that, she says. This really brings that voice over Wi-Fi experience to a cellular-like experience.